Do read again the Taobao listing. They have an option for Shimano (105) 5800 parts, not crappy stuff, though that pushes prices up a few notches.
But the US$450 option is with the most basic of Shimano 3000 series.
Then again, if its support that's a primary concern, yes, its better to buy from a brand with a local presence.
Last edited by maxxevv; 01-07-17 at 02:23 AM.